Plate hook for tensioning printing plates to a rotary cylinder



Aprll 10, 1962 H. J. LUEHRS 3,028,805

PLATE HOOK FOR TENSIONING PRINTING PLATES TO A ROTARY CYLINDER Filed Oct. 51, 1960 2 Sheets-Sheet 1 INVENTOR FH s J 1, (EH/F3 BY 644mm r N/ M5 ATTORNEYS April 9 H. J. LUEi-IRS 3,028,805

PLATE HOOK FOR TENSIONING PRINTING PLATES TO A ROTARY CYLINDER Filed Oct. 31, 1960 2 Sheets-Sheet 2 IZ/Lam 5 ATTORNEYS United v States PatentOfiFice 3,023,805 PLATE HOOK FOR TENSIONING PRINTING PLATES TO A ROTARY CYLINDER Hans J. Luehrs, Westerly, RI, assignor to The Cottrell Company, Westerly, R.l., a corporation of Delaware Filed Oct. 31, 1960, Ser. No. 66,212 7 Claims. (l.'101'-378) The object of my invention is to provide a plate hook of the latter, or tension, type of simple but rugged construction wherein the hook body frictionally engages the walls of an undercut cylinder groove and may be secured in operative position by adjustable means for maintaining said frictional engagement of the hook body and groove walls. 7

Another object of my invention is to provide a plate hook of the character described which is subject to a further adjustment after frictional engagement has been established between the hook body and the walls of the cylinder groove by the application thereto of external force to move the said plate hook and its securing means.

A further object is to provide a plate hook of the tension type in which the above and other objects may eifectively be attained as will appear from the following de tailed specification and as illustrated in the accompanying drawings.

Broadly, my invention comprises a tension plate hook including a hook body, a swingable plate engaging jaw mounted on said body, means carried by said body operable to hold said jaw in a desired position with respect to the body, and other means operable to bring said body into the frictional engagement with the walls of a cylinder groove to hold said body in a desired position on the cylinder, said jaw being adapted to engage gashes in the underside of a plate to tension the latter to the cylinder.

Referring to the accompanying drawings in which the several elements are identified by the same numeral in each figure.

FIG. 1 represents a plan view of a section of a grooved cylinder with plates held thereon by plate hooks constructed according to my invention.

FIG. 2 represents, in side elevation, partially broken away, plate hooks constructed according to my invention, tensioning a plate to its cylinder, plus the tools for manipulating the hook body as desired.

FIG. 3 represents a detail section taken on the line B--B of FIG. 2, looking in the direction of the arrows, the plate having been omitted from this figure. The dotted outline shows the hook and body in position to be removed (or inserted) in the groove.

FIG. 4 represents an end view of the plate hook body shown in FIGS. 1, 2, and 3.

FIG. 5 represents a plan view of the platehook body shown in FIG. 4.

FIGS. 6, 7 and 8 represent, respectively, a plan, end and front views of the plate engaging jaw.

FIG. 9 represents a plan view of the plate hook body clamping member, and,

FIGS. 10 and 11 represent side and end views of the member shown in FIG. 9.

FIG. 12 illustrates the shoulder against which the said clamping member abuts when in clamping position.

A rotary plate cylinder 1, is provided with at least one plate 2, having a plurality of gashes or undercuts 3 in its underside. The cylinder 1 is spirally grooved with grooves 4, said groove walls 5 and 6 being slanted toward each other in the direction of the cylinder surface. Said grooves 4 are adapted to receive therein a plate hook body 7, having its sides 8 and 9 slanted to frictionally engage cylinder groove walls 5, 6 as will be described below. The hook body 7 is vertically bored at 10 to receive the stem 11 of plate undercut engaging jaw 12. The upper section of jaw 12 is indicated by 13, the back surface of said jaw being angled, as shown at 13* in FIG. 7 so that the hook body carrying said jaw may be inserted in a groove 4 through the top of same.

Body 7 is bored to receive a ball 16 in the bore 18 with a spring 17 to urge the ball 16 into detent 15 in stem 11, the opposite end of said spring 17 being based against the inner end of bore 18.

A plate hook body clamping member 19 is located transversely of the hook body 7 and over the top of groove 4 and is removably fixed to said body by a screw 20, operable through member 19 and into the tap 14 in hook body 7 to draw the body sides 8 and 9 into contact with groove walls 5 and 6 by means of a suitable screw driver 21 used to set up on said screw 20.

In the event it is desired to move the body 7 along a groove 4 after screw 20 has been set up a drift 22, as shown in FIG. 2, may be used.

The stem 11 of jaw 12, upon assembly, is peaned over as at 23 (FIG. 3).

In operation, the stem 11 is inserted into bore 10 in body 7 and the end of said stem peaned over after ball 16 and spring 17 are placed in bore 18. I aw 12 is turned parallel to body 7 and the assembly tilted, after having been alined with the desired groove 4, so that the tilted assembly, taking advantage of the angled back surface 13* of jaw 12, may then be dropped into its groove where it assumes a vertical position. law 12 is then swung 45, or to plate undercut engaging position at a suitable angle to the groove, and so held by ball 16 actuated by spring 17 engaging detent 15 and clamping member 19 is then screwed to body 7, the member 19 resting across the top of cylinder groove 4, by setting up on screw 20. Member 19 fits a recessed portion of body 7. When the plate undercuts or gashes 3 have been engaged by jaw 12, the hook body may be moved along the groove, if desired, into final plate registering position by use of a drift 22 (as shown in FIG. 2).

It will be seen that the tightening of screw 20 draws the body 7, engaged by said screws upwardly into a wedging engagement with the slanting walls 5, 6 of the cylinder groove 4.

The jaws may be disengaged from their plate tensioning position by releasing screw 20 and manually moving the hook body 7 along the cylinder groove.

While not essential, it is desirable that the hook body extend longitudinally further from the tap for screw 20 to that end than from stem bore 10 to that end to enable the body to be more firmly seated when screw 20 is set up and to provide a shoulder 24 for the proper alignment and stop for member 19, subject to the driving force of tool 22.

It will be noted that I have provided a tension plate hook of simple but rugged construction having a minimum of moving parts and capable of efiicient operation.

Since it is evident that changes may be made in the form, construction and arrangement of the several elements without departing from the spirit and scope of my invention, I do not intend to be limited to the specific embodiment herein shown and described except as set forth in the appended claims.

What I claim is:

1. A plate hook for securing a plate to a grooved cylinder under tension including the combination with a plate, underside gashes therein, a plate supporting cylinder, and a cylinder groove having converging uninterrupted side walls, of a one piece hook body for frictionally engaging the side walls of the cylinder groove, slanted sidewalls on said body, a turnable plate gash engaging jaw mounted on said body, means for holding said jaw in a plate gash engaging position, and an adjust able clamping member mounted on the hook body across the top of a cylinder groove for vertically wedging said hook body in its cylinder groove.

2. The combination according to claim 1 in which the cylinder groove is of less width at its top than the width of the hook body.

3. The combination according to claim 1 in which the cylinder groove walls engage the slanted side walls on said hook body when the body is wedged in said groove.

4. The combination according to claim 1 in which the back of the plate gash engaging jaw is so angled that when said jaw is parallel with the hook body the total slanted width of the jaw and body is less than the top width of the cylinder groove whereby the body may be inserted into the groove through the top.

5. The combination according to claim 1 in which the jaw has a stem, a dent in said stem and the means for holding the jaw in plate gash engaging position comprise a spring pressed ball in the body adapted to engage said dent in the said stem and releasably hold said stern in its adjusted position.

6. The combination according to claim 1, in which a screw is mounted in the clamping member and threaded into the hook body for vertically wedging said hook body in its cylinder groove.

7. The combination according to claim 1, in which an abutment is provided on the clamping member for engagement by a tool for moving the hook body along the cylinder groove.

References Cited in the file of this patent UNITED STATES PATENTS 772,219 Cottrell Oct. ll, 1904 2,310,547 Roesner Feb. 9, 1943 2,667,834 Ziebell Feb. 2, 1954 

